Not too rough, if you don't mind ordering from China. Check out this camera on ebay.

It actually sports a Full HD CMOS USB Camera, which shoots at 30 / 60 / 120 FPS. It's going for $45.26 US, plus 99 cents shipping, but it looks like it meets your specifications.

There's also this one for $49.62, which also appears to meet the speficications.

Note that both of these have limited supply, so you may or may not be able to get hold on enough for your project.

Not too rough, if you don't mind ordering from China. Check out this ELP-USBFHD01M-L36-120FPS on ebay. It's unbranded, but I've given you the model number so you can find it elsewhere. Currently, the cheapest place I can find is ebay, but that could change, as per comments.

It actually sports a Full HD CMOS USB Camera, which shoots at 30 / 60 / 120 FPS. It's going for $45.26 US, plus 99 cents shipping, but it looks like it meets your specifications.

There's also this ELP-USBFHD01M-L36-120FPS for $49.62, which is actually the same camera from a different ebay seller.

Note that both of these have limited supply, so you may or may not be able to get hold on enough for your project.